I try to do this... but I just don't have it in me. I save another file completely and then merge.
@Shanny8 I had an alarming calmness when my hard drive crashed (lol). I mean, everything was gone! Old freelance, scribbles, photos, music, my old comic pages... but because I had my working file of my comic saved (miraculously) to the computer I was okay. Again-- loosing all that reference material is what killed me. Luckily, I also used google drive and some text reference were saved, but photo reference? Super hard to replace-- it takes hours of searching!
Man, when you can, upgrade your dropbox! My dropbox serves as a backup storage for all my digital work but it's also handy to transfer files to people (like you said). Most people I freelance with use dropbox (it makes things easier for me to just have an acct). I write off the expense each year.